I am using Hibernate 4.2.4 and I am interested to know how Hibernate translate a session.get call to an equivalent sql query that is eventually used to retrieve rows from database. I do not want to log the generated sql in console. I want to use the same sql query in my application. Something like below.
...
SessionFactory sessionFactory = configuration.buildSessionFactory(builder.buildServiceRegistry());
// I want the query string here
String query = sessionFactory.someUnknownMethod(Some Paramters);
Session session = sessionFactory.openSession();
// actual session.get query
Comment comment = (Comment) session.get(Comment.class, new Integer(1));
...
I have seen this thread for Criteria query -> How to get SQL from Hibernate Criteria API (*not* for logging).
I would like to know if similar procedure exists for session.get type queries.
I have also seen this thread -> get SQL from hibernate get
where the question is exactly same as mine, but the accepted solution talks about fetching statistics which, to my understanding, only accounts for the queries that have already been executed. Plus, from statistics I was able to catch hql/sql queries but not session.get queries.
I want to know if there is a way for a user to generate and use the sql even before the actual session.get gets executed (possibly by following the same path as hibernate).
Related
I have query in SQL like
select part_no, base_price, fn_get_ecom_item_new_price(Company_id, Part_No, Unit, Price, 'N') newPrice from ecom_prodmast
if there is an option to run the same query in hibernate? there is any other way to execute a select query with function in hibernate?
You can use session.get() method from Hibernate and the generated Java classes, then will look something like that:
SessionFactory factory=cfg.buildSessionFactory();
Session session=factory.openSession();
Transaction t=session.beginTransaction();
Economy e= (Economy) session.get(Economy.class, part_no ....);
t.commit();
session.close();
return e.getData();
The main Economy class should be configured to hold your data like part_no, base_price, fn_get_ecom_item_new_price, etc. of your ecom_prodmast table. That means first configure Hibernate and generate the classes, then use them. You can find examples on the internet on how to.
If you are using Eclipse is even simpler, because it exists a plug-in that does that for you.
If you want to access the procedure, that should also exist in the generated files and you call it as a simple function.
Yes,
use a native query.
Here is a link to Chapter 16. Native SQL.
For more information,
try a google search for "hibernate stored procedures mysql",
there are about a million hits.
I already have an existing code base, where schema(like db_1, db_2..) are created at run time.
We are currently using JdbcTemplate, using that its quite easy to append schema in the native SQL queries some thing like :-
sql = " Select * from "+schema+".user";
jdbcTemplate.query(sql, new UserMapper());
Now I want to know is how to provide schema to hibernate at runtime like I did with the jdbcTemplate?
What connection url should I provide in hibernate.cfg.xml so that it doesn't connects to a single schema rather whole database?
Any suggestions will be helpfull.
P.S: I am new to hibernate (So I might have missed something stupid)
I know of two options:
Use native SQL query binding results to JPA entities. Details here.
Use Hibernate multi-tenancy. Details here and here.
Although I haven't tried either.
im familiar with this following way to delete the data (just the data ,not the entity itself)
from the entity
entityManager.getTransaction().begin();
entityManager.createQuery("DELETE FROM " + className)
.executeUpdate();
entityManager.getTransaction().commit();
there is another way to do that like to provide the entityname and then reomve all the data .
You're not using SQL in your code but JPQL, JPA Query Language.
There is no other way to delete all data at once, except by loading all of them and deleting them one by one. It's not even possible with criteria queries since they don't support delete operation yet.
Well.. in this case both NativeSQLQuery and JPQL resolve to the same thing. What you did is JPQL way. The following you could write a nativeSQLQuery
EntityManager em = ...;
Query query = em.createNativeQuery ("SELECT * FROM EMP", Employee.class);
I have two tables website_availability and status_codes.And these have foriegn key relation between them.status_codes is parent table.I am using hibernate.I need "list" of values from these tables after joining.I am following this code.
List<WebsiteAvailability>list=new ArrayList<WebsiteAvailability>
String selquery="select w.statusCode,w.updateTime,w.statusCodes.statusCodeValue from WebsiteAvailability w,StatusCodes s where w.statusCodes.statusCode=s.statusCode and w.url=?";
//here hibernate generates the POJO classes and these are having foriegn key relation so WebsiteAvailability is having private StatusCodes statusCodes.So I am accessing statuscodevalue of statuscodes table using w.statusCodes.statusCodeValue.
PreparedStatement ps=con.prepareStatement(selquery);
ps.setString(1,selUrl);
rs=ps.executeQuery();
while(rs.next())
{
list.add(new WebsiteAvailability(rs.getString("statusCode"),rs.getTimestamp("updateTime"),rs.getString("statusCodeValue")));
}
return list;
}
First of all can I use resultset with hibernate.Is there any alternative for this.Because as I am using ? placeholder I should use preparedstatement for setString().And executeQuery() to get the list.I need list of values how can i get.Am getting empty list.What is the error?
org.hibernate.QueryException:could not resolve the property statusCode of -----WebsiteAvailability---
In the hibernate mapping file I have checked for case sensitivity.Still getting could not resolve property exception
You're trying to execute an HQL query, working on Hibernate entities, as a SQL query, using JDBC statements. That doesn't make sense. HQL queries are executed by the Hibernate Session. Not by JDBC. If you're using Hibernate, you don't need JDBC anymore (except maybe in some corner cases when you need raw JDBC performance, like batches).
Read the documentation about HQL query execution. You'll also have to fix your query, because it doesn't seem right. It contains w.statusCode and also w.statusCodes. It also does a join using equality statements and selects from two entities, instead of simply using implicit or explicit joins. Those are also explained in the documentation.
Using a Session a named query can be retrieved like following:
Query query = session.getNamedQuery(queryName);
But how can a named query be retrieved without using a session?
I am modifying the query-string dynamically and don't need a Session at that moment.
The defined named-query is not changed
SessionFactoryImplementor sesionFactoryImplementor=(SessionFactoryImplementor)sessionFactory;
sesionFactoryImplementor.getNamedQuery("test").getQueryString();
Works with Hibernate 4. As Nayan Wadekar, commented you can not modify it at runtime.
This works well for me:
Query query = em.createNamedQuery(namedQuery);
String hql = query.unwrap(org.hibernate.Query.class).getQueryString();
Hope this helps!